[TowerTalk] blown 10m section of ICE419 again

[Keith Dutson]

I have a pair of 419A and a pair of 419B.  The A's have been to many
DXpeditions, installed behind Kenwood 480HX's (200W).  The first problem
happened back in 2004 in Falklands (VP8WWW).  We were working into a Hustler
vertical.  The problem happened when the radio band was changed to 20M but
the 419 was left in 10M.  It does not take long to heat up the caps when
this happens.

I have made repairs to all four units ovet the years.  Ten meters has the
highest failure rate, but 15 and 20 have also been damaged.

Thanks to advice from Dave Hachadorian K6LL, I have replaced caps to
increase tolerance for off-band operating errors.

Another thing I have done is attach an instruction sheet to each unit to
help lower the chance for operator error.  I have pasted the sheet below,
but it is from a Word document that is formatted better for printing.  It
can be sent separately for anyone who wants it.

An even better solution is to switch bands automatically when the rig band
changes.  I use the Bandmaster from Array Solutions to do this.

73, Keith NM5G

419 instruction sheet:
----------------------------------------------------------------------------
---------------------
ICE Bandpass Filter Model 419 Instructions

DO NOT TRANSMIT INTO THE FILTER UNTIL THIS PROCEDURE HAS BEEN PERFORMED.

This procedure applies to both models 419A and 419B.  Max input power is 200
watts.

INITIAL SETUP

1.	Connect the filter between the transceiver and tuner/amp/antenna.
Placing the filter after the tuner increases the risk of overvoltage.  Use
of an internal transceiver tuner is not recommended, but may be okay if it
matches VSWR 3:0 or less.
2.	Follow CHANGING BANDS procedure below.

CHANGING BANDS

1.	Set the POWER switch on the filter to OFF.
2.	Set the BAND switch to match the band selected on the transceiver.
3.	Set the POWER switch on the filter to ON.
If the transceiver is on a band not covered by the filter, leave the power
switch off; this will bypass the filters.


***NEVER*** TRANSMIT INTO THE FILTER WHEN THE BAND SWITCH LIGHT DOES NOT
MATCH THE TRANSCEIVER BAND!
----------------------------------------------------------------------------
---------------------

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of WW3S
Sent: Wednesday, October 02, 2013 5:16 PM
To: towertalk at contesting.com
Subject: [TowerTalk] blown 10m section of ICE419 again

Both ICE 419 filters blew the 10m side again....both were already repaired
using the CDE 1000v series caps from Mouser, one had 2 270 pf in, and the
other had 3 180 pf.....the one with 2 blew almost right away, the one with 3
lasted a 2-3 hours maybe....running just 100w into a Cushcraft A4 with what
appears to be low enough SWR.....before I order again from Mouser, any
ideas? 

73, Jamie WW3S

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk